The resurvey of both a geodetic network and a levelling line, soon after a seismotectonic crisis which occured inside the subaerial rift of Asal--Ghoubbet in Afar, shows an horizontal extension of about 2 m and a vertical movement up to 70 cm. These movements showed clearly the mechanism of rifting in a setting similar to a typical oceanic rift valley. The observed data are well explained by a brittle elastic model and a rebound mechanism.